The invention relates to a process and a plant for the deoxidation of water, in particular of sea water, which for the removal of its oxygen content is brought into contact with a gaseous propellant, which propellant is circulated in a circulation and the oxygen being removed from the propellant laden therewith in a device by catalytic combustion by means of a fuel gas. A widespread method for deoxidisation consists in the degasification of the water in a multi-stage vacuum column. However this is very expensive and associated with high energy consumption. In addition further corrosive and expensive chemicals have to be used for the removal of remaining traces of oxygen. In the light of all these problems an attempt was made to deoxidize the water by means of a closed gas circulation, as is described, for example, in EP Application 0327491. Even these processes, in which, for example, natural gas is injected as the fuel gas through a separate line into the catalyst bed, have serious disadvantages and problems. Thus relatively expensive plants with large circulating devices, precise metering devices and monitoring devices are required in order to be able always to maintain the necessary gas compositions in the circulation operation and to exclude operational errors. Furthermore additives and associated metering and monitoring devices, which are also expensive, are required. Most importantly of all there is the risk of explosion in these relatively large plants. In practice it is not possible to exclude a leakage. Therefore the entire plant has to be made explosion-proof and for this purpose, for example, be provided with an additional expensive ventilation device, which consumes energy and requires a lot of space. However often this is not at all possible for reasons of space, e.g. on platforms or on ships and in particular not when retrofitting existing plant. If the necessary pressure in the circulation is maintained by the addition of nitrogen, this in turn requires too great consumption of nitrogen. On the other hand when air is used as the pressure maintaining agent, there is an additional consumption of fuel and unacceptably high CO.sub.2 production.
The object of the present invention is therefore to overcome the disadvantages of the known processes and in particular to create an explosion-proof process, which does not require any expensive protective measures. In addition it should be possible to control the plant simply and with a high level of operational safety, to use little fuel and energy and not to give off any pollutants, including CO.sub.2, to the atmosphere.